JDK1.42_03 + Tomcat5.0 + JCreator生成Excel表问题。

livepower

最近下载了一个jxl。但我进行开发的时候老是报错，请问怎么解决呀！
package com.jxclic;
import java.io.*;
import java.util.*;
import com.jxl.*;
import com.jxl.write.*;

public class Excel{
        public static void doWriteExcel(OutputStream os){
                com.jxl.write.WritableWorkbook wwb = Workbook.createWorkbook(os);
        }
       
        public static void main(String args[]){
                System.out.println("Excel Test...";
                try{
                        File fileExcel = new File("Test.xsl";
                        fileExcel.createNewFile();
               
                        OutputStream osFile = new FileOutputStream(fileExcel);
                }catch(Exception ex){
                        System.out.println("Error!"+ ex.getMessage());
                }
                doWriteExcel(osFile);
        }
}
D:\JAVA\JCreator\JX\Excel.java:17: cannot access com.jxl.write.WritableWorkbook
bad class file: D:\JAVA\JCreator\JX\com\jxl\write\WritableWorkbook.class
class file contains wrong class: jxl.write.WritableWorkbook
Please remove or make sure it appears in the correct subdirectory of the classpath.
                com.jxl.write.WritableWorkbook wwb = Workbook.createWorkbook(os);
                             ^
1 error

Process completed.

这里可能是没有正确设置CLASSPATH。用别人写的类库应该放到什么地方呀。